1. Field of the Invention
The present invention relates to cleaning equipment for cleaning a wafer surface with a mixture of various chemicals.
2. Description of Related Art
In conventional types of cleaning equipment, when it is necessary, for instance, to sequentially clean a number of objects (such as wafers), at first a mixture of chemicals is put in a vessel such as a beaker, and then an object to be cleaned is steeped in said mixture of chemicals, and after it is taken out from the mixture of chemicals, the next object to be cleaned is steeped in the mixture of chemicals, thus this step being repeated.
With the construction based on prior art as described above, however, as objects to be cleaned are steeped sequentially in a mixture of chemicals, an object cleaned later in the mixture of chemicals is steeped in a more contaminated mixture of chemicals, which is not preferable.
In this case, such a method as exhausting a mixture of various chemicals with a compressing means (a pump) for sequentially cleaning objects to be cleaned may be used. In this method, such problems as corrosion of the compressing means (a pump) may occur due to the chemicals. An object of the present invention is to provide, for the purpose to solve the problems as described above, a cleaning equipment in which objects to be cleaned can sequentially and repeatedly be cleaned without being contaminated and such problems as corrosion due to chemicals used for cleaning can be prevented.